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How to drain gas tank

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Old 10-12-17, 02:58 PM
  #51
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Originally Posted by GSLSEforme View Post
Use a turkey Bastet and inject about 20 cc of engine oil into each leading plug hole. Turning fan is...turning fan against fan clutch which does not turn engine over. Easiest way is to grab a/c compressor drive belt and pull toward you. This belt is connected directly to e shaft=crankshaft in piston engine. Pulling on belt will turn engine over,reach down as far as you can on top run of belt and pull,you'll get about 6" of belt in one pull. Do this about 20x,that will give you about 6 revolutions of the engine. Will caution you to not pinch your hand between belt and a/c pulley.
Ugh! I removed the AC belt a long time ago because of an issue with the compressor...

what if I just cranked the engine for 1/4 sec 6x ?
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Old 10-12-17, 03:19 PM
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Originally Posted by RXrick View Post
Ugh! I removed the AC belt a long time ago because of an issue with the compressor...

what if I just cranked the engine for 1/4 sec 6x ?
Or put a 19mm socket on a break bar and and put that in the eshaft bolt and turn it over a few times slowly.
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Old 10-12-17, 06:37 PM
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^^^^ this...i was trying to suggest easiest way for you to turn engine over. You want to turn engine slowly by hand to allow oil to spread out uniformly around housing and rotor. Spinning it with the starter-even short bursts? will be too fast and just push the oil out of plug holes and exhaust ports defeating the purpose. Want to reiterate,strongly suspect engine is mechanically ok. Been repeatedly flooded and compression likely low because of loss of oil film from all the fuel... Do not know if you're in a rural area but want to suggest you remove air cleaner lid and pull air filter out and look down in bottom of air filter housing for any rodent infestation=mouse nest material. May want to remove air intake tube that runs across front of car from air filter inlet to be sure it's clear. Likewise remove air intake boot between airflow meter and upper chamber of intake manifold and make sure there's nothing in there. Use a mirror and look into airflow meter for obstructions-or my preference is remove complete air cleaner assembly so you can look inside airflowmeter from both sides and carefully manipulate flap door to be sure it is free. There will be slight resistance (spring) and should return to closed position smoothly/consistently.
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Old 10-12-17, 07:04 PM
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Brief explanation of airflow meter: when engine is cranked over the air it pulls in(through airflow meter,air filter housing) causes the flap door to move slightly open,this closes a set of contacts that completes fuel pump circuit allowing it to build pressure to start car. This is why car always cranks a few revolutions before it fires up. Once running,engine pulls more volume of air in causing door to open proportionate to throttle applied. The pivot the airflow meter flap door rides on is attached to a wiper that slides across a carbon variable resistor sending an ever changing signal to ECU for fuel quantity calibration dependent on throttle opening. ANYTHING that impedes either airflow or physically binds the flap door can potentially cause ALL the symptoms you're experiencing. Lack of sufficient amount of air to support combustion? I strongly suggest you diligently examine all the air intake pieces mentioned. The car has sat more than long enough for critters to have made it their home,have seen this scenario enough times on cars,trucks,motorcycles over the years i could write a book on it. For all the time you've spent working on the car trying to get it to run,spend some time here before continuing to try starting car. This could be the proverbial wild goose chase but all it will cost you is your time and again this is money you'd be paying someone at shop rate to investigate what you can do for yourself. Should all this prove fruitless,video your next start attempt so we can see/hear it and maybe pick something out that may help.
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Old 10-12-17, 08:07 PM
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Originally Posted by GSLSEforme View Post
^^^^ this...i was trying to suggest easiest way for you to turn engine over. You want to turn engine slowly by hand to allow oil to spread out uniformly around housing and rotor. Spinning it with the starter-even short bursts? will be too fast and just push the oil out of plug holes and exhaust ports defeating the purpose. Want to reiterate,strongly suspect engine is mechanically ok. Been repeatedly flooded and compression likely low because of loss of oil film from all the fuel... Do not know if you're in a rural area but want to suggest you remove air cleaner lid and pull air filter out and look down in bottom of air filter housing for any rodent infestation=mouse nest material. May want to remove air intake tube that runs across front of car from air filter inlet to be sure it's clear. Likewise remove air intake boot between airflow meter and upper chamber of intake manifold and make sure there's nothing in there. Use a mirror and look into airflow meter for obstructions-or my preference is remove complete air cleaner assembly so you can look inside air flow meter from both sides and carefully manipulate flap door to be sure it is free. There will be slight resistance (spring) and should return to closed position smoothly/consistently.
20cc = 1.4 tablespoons. Is that what you suggest I put in the bottom rotors?

I was going to put the oil in as you suggest and then put the plugs back into the engine. So cranking it with short burst would not spit the oil out of the plug holes but didn't know about the exhaust ports. But I think I can see what you mean, I would also be introducing fuel at the same time anyway?

Putting a 19mm socket on the eshaft bolt looks like I have to remove a lot of things in front to get to that. And I don't even know what that is, but I assume its a bolt in the middle of the (crank) shaft independent from the fan...

The car has been garaged. It last ran in July 2015, and like a champ. Everything came crashing down when we fixed the leak at the fuel pump, and then the fuel pump stopped working. Strange set of coincidences? Replace fuel pump with a used pump I bought from someone here in the Club. It wasn't an exact replacement but would work, or so I was told. It does work (the last time I listened) but now I wonder if it is producing the proper pressure or flow.

Before I remove all the air induction system and inspect that, I want to test the fuel pump again. To Test: If I jump the two connectors on the black rubber cover connector at the air pump (see previous photos) does the ignition have to be ON? Or can I jump it without keys in the ignition? I believe this test will allow me to HEAR it running. Yes?

As for inserting oil into the bottom rotors and lubricating the rotors and housing, I will need to figure out another way to move the crankshaft. Maybe I will have to put an AC belt on to do that...

20cc = 1.4 tablespoons, yes?
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Old 10-12-17, 08:32 PM
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About 1 1/2 tablespoons yes. Put a ratchet,suitable extension and 3/4" or 19 mm socket onto center bolt middle of lowest pulley and turn clockwise thru several revolutions. Putting oil in and cranking with plugs in will just foul plugs with oil and gas,serves no purpose.. jump 2 terminals on connector,turn key to on will run pump.
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Old 10-12-17, 09:36 PM
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On a whim,...

Tell us some more about that fuel pump you bought from a forum member.

You do realize that the EFI system on the -SEs relies on a high pressure fuel pump which puts out 40-60psi vs the 2-3psi which a carbeurated car would use, right? The SE fuel pump would be unique to this model. Also, if it was purchased used, did you bench test it to ensure adequate flow?

Do you still have the old fuel pump you removed?
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Old 10-12-17, 09:45 PM
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Originally Posted by GSLSEforme View Post
About 1 1/2 tablespoons yes. Put a ratchet,suitable extension and 3/4" or 19 mm socket onto center bolt middle of lowest pulley and turn clockwise thru several revolutions. Putting oil in and cranking with plugs in will just foul plugs with oil and gas,serves no purpose.. jump 2 terminals on connector,turn key to on will run pump.
Thank you. I will do all but not sure in what order. I will post a photo of my pulleys and you tell me which one (lowest?) I should crank.
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Old 10-12-17, 10:30 PM
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Originally Posted by LongDuck View Post
Tell us some more about that fuel pump you bought from a forum member.

You do realize that the EFI system on the -SEs relies on a high pressure fuel pump which puts out 40-60psi vs the 2-3psi which a carbeurated car would use, right? The SE fuel pump would be unique to this model. Also, if it was purchased used, did you bench test it to ensure adequate flow?

Do you still have the old fuel pump you removed?
I don't know if I still have the original pump but I have a photo of it alongside the one I purchased, and according to the invoice, it reads "used aftermarket fuel pump for a 1984 Mazda RX-7 GSL-SE 13B model." (see photo it's obvious which is the original.) And no, I did not know anything about a 40-60psi high pressure fuel pump vs any other pump... Outside this forum, getting accurate info about this car has always been a concern of mine.
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Old 10-12-17, 10:43 PM
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Originally Posted by RXrick View Post
I don't know if I still have the original pump but I have a photo of it alongside the one I purchased, and according to the invoice, it reads "used aftermarket fuel pump for a 1984 Mazda RX-7 GSL-SE 13B model." (see photo it's obvious which is the original.) And no, I did not know anything about a 40-60psi high pressure fuel pump vs any other pump... Outside this forum, getting accurate info about this car has always been a concern of mine.
Looks like maybe this is what I need? (This image is from Atkins Rotary = $370.)
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Old 10-13-17, 05:29 AM
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Originally Posted by RXrick View Post
I don't know if I still have the original pump but I have a photo of it alongside the one I purchased, and according to the invoice, it reads "used aftermarket fuel pump for a 1984 Mazda RX-7 GSL-SE 13B model." (see photo it's obvious which is the original.) And no, I did not know anything about a 40-60psi high pressure fuel pump vs any other pump... Outside this forum, getting accurate info about this car has always been a concern of mine.
Yes,that is a high pressure FI pump,don't know brand or quality but looks new compared to old. Jumpering the test connector to hear it run is a good idea,better yet and what would put the whole fuel pump/pressure question to rest would be to tee in a fuel pressure gauge for an exact reading. Like compression gauge mentioned in a previous post,this could be rented fro an auto store,some stores have loaner tool programs. This is not hard to do,your model of car is very easy/quick to perform this test on. If interested I can take pics of what gauge looks like,where to install it and how to test fuel pressure.
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Old 10-13-17, 06:53 AM
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Originally Posted by RXrick View Post
Looks like maybe this is what I need? (This image is from Atkins Rotary = $370.)
I'm from the camp that insists on proving a part is defective before replacing it,that said i replaced my pump a couple years ago. It still worked fine and i kept it for a backup/parts. I replaced all the rubber lines in complete fuel system with ethanol compatible fuel hose and replaced the pump along with the lines because of its age. I installed the oe pump assly. pictured. I paid less than that advertised price shipped to me,shop around,they are still available from Mazda dealerships. I had to wait about 8 weeks for it but was in no hurry as my car was getting a thorough mechanical restore/upgrade at the time.
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Old 10-13-17, 07:33 AM
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Originally Posted by GSLSEforme View Post
Yes,that is a high pressure FI pump...This is not hard to do,your model of car is very easy/quick to perform this test on. If interested I can take pics of what gauge looks like,where to install it and how to test fuel pressure.
Which pump are you talking about (high pressure FI pump)? The old one or the shiny one?

Yes, please post pics of the pressure gauge and where and how to test the fuel pressure. Thanks!!
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Old 10-13-17, 09:39 AM
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Originally Posted by RXrick View Post
Which pump are you talking about (high pressure FI pump)? The old one or the shiny one?

Yes, please post pics of the pressure gauge and where and how to test the fuel pressure. Thanks!!
They are both hi pressure pumps,original and replacement.
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Old 10-13-17, 06:31 PM
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Ok,had time to take some pics. Pics my fingers are pointing to is fuel return line. The feed line from the pump is the more forward facing hose,this is where you will tee in your gauge. Slide off hose clamp(original hoseclamps are spring loaded. I replaced my fuel line and used new FI hose clamps) with some needle nose pliers and twist hose to loosen. Be careful to not twist the steel line removing the hose> A lot of SE models with age on them,mine included prove difficult to remove these hoses. I was renewing my fuel hose so i used a razor blade and sliced hose lengthwise at the ends to be able to work them off easier. You may wish to plan on replacing these sections of fuel hose . Pull line off and install the hose side of the tee to the steel fuel line and clamp in place. Insert opposite barbed end of tee into line that was removed and clamp in place. Jumper the fuel test connector,turn key on and read fuel pressure on gauge In this scenario,fuel pressure should be between 50-70 psi. Fuel pressure with engine idling should be about 30 psi.
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Old 10-14-17, 08:34 AM
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Originally Posted by GSLSEforme View Post
Ok,...Jumper the fuel test connector,turn key on and read fuel pressure on gauge In this scenario,fuel pressure should be between 50-70 psi. Fuel pressure with engine idling should be about 30 psi.
Thank you! I will get a kit from Auto Zone. Will the pressure results be immediate or will it take several seconds? And will this test give any indication of the health of my fuel filter also? If I don't get the necessary pressure how will I know if the problem is with the pump or fuel filter? Thanks!
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Old 10-14-17, 09:55 AM
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On a healthy pump, it will register pressure immediately and hold steady and have a subdued hum while running. Pressure should be what i posted previously,if lower than minimum spec,check voltage at pump while it's running. Regarding fuel filter,you stated previously you replaced it,car has accrued no mileage. Aside from possibly having some junk in it from a dirty,possibly rusty tank,should be ok. If pressure comes up immediately,that's good enough proof for now. When you turn key off,fuel system should hold pressure for at least 1/2 hour,preferably longer,so leave fuel pressure gauge attached for some time after done testing. The longer the system holds pressure is a good indication that internal parts of system are intact. Also a lot less messy if you wait til system pressure bleeds off to near zero before you disconnect gauge. In pic of my gauge,the smaller hose coming out is for venting fuel pressure into a container by pushing the button above it,allows me to disconnect gauge immediately after finishing pressure tests which saves time and less messy. All gauges don't have this feature,the one you borrow/rent may not.
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Old 10-14-17, 10:05 AM
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Check your PMs.
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Old 10-14-17, 11:14 AM
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Originally Posted by GSLSEforme View Post
On a healthy pump, it will register pressure immediately and hold steady and have a subdued hum while running. Pressure should be what i posted previously,if lower than minimum spec,check voltage at pump while it's running. Regarding fuel filter,you stated previously you replaced it,car has accrued no mileage. Aside from possibly having some junk in it from a dirty,possibly rusty tank,should be ok. If pressure comes up immediately,that's good enough proof for now. When you turn key off,fuel system should hold pressure for at least 1/2 hour,preferably longer,so leave fuel pressure gauge attached for some time after done testing. The longer the system holds pressure is a good indication that internal parts of system are intact. Also a lot less messy if you wait til system pressure bleeds off to near zero before you disconnect gauge. In pic of my gauge,the smaller hose coming out is for venting fuel pressure into a container by pushing the button above it,allows me to disconnect gauge immediately after finishing pressure tests which saves time and less messy. All gauges don't have this feature,the one you borrow/rent may not.
Perfect explanation! Exactly what I needed to know/learn. I hope to do this test today or tomorrow. I will post the results here for all to see/read. Thank you very much for your time!!
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Old 10-14-17, 11:19 AM
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This is basically the same thread over and over again for GSL SEs. Check the fuel pressure AND the volume If either is bad or marginal take out your tank, clean and seal it, there are a lot of good kits out there. Do a proper compression check. This is where most running problems with the GSLSEs lie. Since you have spark I bet this is why you are having problems.
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Old 10-14-17, 12:11 PM
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Originally Posted by andernamen View Post
This is basically the same thread over and over again for GSL SEs. Check the fuel pressure AND the volume...
This tread started out about "bad gasoline" as a possible issue and then evolved into all of this. This forum is fantastic but searching thru 1000s of post and poor thread "titles" is very frustrating and time-consuming. I wish there were categories for "years" then "models" and then "subject sub-categories" and then within this sub-category the post with accurate descriptive "titles" defining the subject matter. The 1st, 2nd, 3rd generation categories can be better defined, and then there are all the miscellaneous posts/threads... Personaly, I ignore post with "non-descript titles" that don't describe what the subject or content is about. If this forum was a company website most visitors would most likely be very frustrated trying to find thebexact information they are looking for, quickly and easily. IMHO.

Mazdatrix sells a brand new GSLSE gas tank for $523. If this was my problem I would have opted for this solution a long time ago, but I wondered if draining the tank and putting fresh gasoline in would be an easy way to remove the "bad gasoline?" idea as my problem. Hence my post, "How to drain a gas tank?" in the 1st Generation category.
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Old 10-14-17, 07:05 PM
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fuel pressure test kit

Picked this up from Auto Zone today. It's a loaner. $164 deposit that is refunded when you return it. I have 3 days. There's a lot of little parts probably for a lot of little fittings. It comes with instructions and the instructions from GSLSEforme are clear so I will attempt to do this test tomorrow (Sunday) and I will try to record the fiasco so you can see what I did and how it went..I have a couple fire extinguishers
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Old 10-14-17, 07:17 PM
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Looks like you have everything you'll need,can see the tee fitting you will use,gauge will screw right to that. Easy,peasy.
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Old 10-15-17, 02:39 PM
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Originally Posted by GSLSEforme View Post
Looks like you have everything you'll need,can see the tee fitting you will use,gauge will screw right to that. Easy,peasy.
Fuel pressure test setup pics
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Old 10-15-17, 03:30 PM
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Fuel Pressure Test FAIL

At first nothing happened. Pump did not run. So I changed my jumper from a solid copper wire to another solid copper wire (see photo) and on my second attempt the pump ran, but the pressure gauge did not move.

I recorded what the pump sounds like when it runs. I will post that next.
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